When British Ambassador Fanshawe (played by Malcolm McDowell) asks Shawn where he learned his fake British accent, Shawn mentions "Phineas and Ferb's grandfather." McDowell provides the voice for grandfather Reginald Fletcher on Phineas and Ferb (2007).
One of the toys shown in the opening sequence is a John Cena action figure. John Cena was on a previous episode playing Juliet's brother.
Malcolm McDowell is a frequent recurring character on The Mentalist, a show Psych often pokes fun at for copying their show
Spot the Pineapple: on the bannister at the Ambassador's residence.
The pool where the body was found is the same set as the Inn pool in the Supernatural episode Playthings (2x11). Supernatural and Psych sets were near each other. It's also the same set from the FIFTY SHADES OF GREY (trilogy)